Testing- stophus dioxide



Aug. 24 ,1926.

W. C. DEVER TESTING SULPHUR DIoxIDE original Fild August 1. 1925 FIS' 4 MZZim C Oever [zzz/022 or A ozcjys `Patented Aue. 245, i552@ uN-lprso erg-Me WILLIAM C. DEVER, OF DETROT, `MlCrl'ldt, ASSIGNOR rTO KELVINATOR CORPORA- TION, OF DETROIT, `Iliffl(LHGrAll', i

arsu'rf oFFficl-.

A COREORATION OF MICHIGAN.

` TESTING suiirnus Dioxins.

`Original application led. Augustll, 1h25, Serial No. 47,1507! yDivided and this `application led March Sy i Serial No. 93,128.

This invention relatesto mechanical `refrigeration and has for its object the proin addition tothe moisture enhances the 'corrosiveeffect with the result lthat pistons bind, valves stick7 pipes become corroded, and lubrication is injured; while if the refrigerant be anhydrous it exhibits no in- "1 jurious ei'l'ect upon the mechanism I have discovered that the maximum permissible water content is about .06% and the herein described improvements in apparatus and method have been devised for the purpose of facilitating analysis by comparatively untrained menand equally available to the maker andthe user` of sulphur dioxide.`

`This application is a division of my prior application No. 47,507, filed August 1, 1925.`

in the drawings accompanyingand forining a part of `this application Fig. 1 illustrates a` preferred embodiment of my com-` plete improvedapparatus as employed in connectionwithiiny improved process; Fig.

\ 2 is a .sideelevation of a simplified apparatus for the performance of my testing process; Figjv is a sectionalview corresponding to the lines 3-3- of Fig. 2; and Fig. l is a rear-elevation ofthe apparatus shown in Fig. 2.x i

1 denotes a glass vessel having a cylindrical mouth 2adapted for thereception of. a rubber stopper 3 or` other tightly fittings, removable closure, andhaving its lower `end f reduced in diameter to form a prolong t which in turnV i's again reduced` to forni a second prolonga 5, the latter closed vby an integral bottoni 6. In the form shown the body of the vessel thus producedhas a capacity of between 200 and 300 cubic centimeters, the prolonga a capacity of approximately 1 cubic centimeter andthe `prolong 5 acapacity of approximately lcubic centimeter. I" have found the following `ap- "Vproxirnate dimensione very convenient; di-` aineterof body 11/2;inch, length of upper` cylindrical portion 8 inches; diameter `of first prolong -11@ inch; length of first Iprolong Y1FL/2 inch; diameter of second-prolong -g inch; length ofsecond prolong lzinch;`

total length of tube 10 inches.

This tube is accurately graduated on the lower prolong to 1/100 of a cubic centimeter. rihe larger prolong is graduated to 33()- cubic centimeter; and thelower tube-v portion .is graduated at 25,` 50, 75, and.

100 c. c. although the 100 c.- c. mark is by far the vmost importantythe others being` little -if ever used. i Y

This tube is here` shown as coupled by means of a glass tube 10` and rubber connection 11 tothe inlet connection 12 of a suitv the sleeve 11 when thetube `10 is discon-` nected.` The inlet connection 12 has an internal projection-18l leadingpto the lower end of the device and the body in use is filled with some loosely packed highly hydroscopic substance. The best material for this purpose that I have so far discovered is asbestos wool or other inert materialA thoroughly impregnated with powdered!y phosphoric anhydride (P205). The top and bottom of the absorptiontube are preferably stuffed with asbestos wool7 not impregnated7 toprevent clogging. i p i i `The outlet neck17 ,is connected by the rubber sleeve 20,(to a bent glass tube21 which dips beneath the surface of a quan-V ti-ty vof concentrated sulphurio acid in :the container 22.` This container is. also `provided with a discharge tube 23, both the tubes21 and 23 being received in a tight fitting rubberstopper21l. The tube 23 leads to somepoint of `convenient discharge for r thesulphur dioxide.v t v v e .i l

"The apparatus is prepared for the test as follows: Into the bottom of the absorption tubeyl is put athinlayer of asbestos wool to 4prevent* obstruction of thetube 18. `The body of the tube is then filled to within about an inch of the top with a -dry mixture or the asbestos wool (or other inert liller) and phosphoric anhydride. The space above is then lilled with asbestos kwool or the like tightly packed in after which the stopper 16 is applied. The phosphoric anhydride mixture can be made on any dry day without any undue absorption'o-t'moisture if everything is first` got to hand and no undue delay is permitted; Sulphur dioxide gas must then be passed through the bulb for at least two hours after recharging and for fifteen minutes afterftliebulb has stood overnight. ThisV can readily be done' by Ine'aiisof the appar'atus'slrown' in the Adrawings-ja f quantity of 'sulphur dioxide being introduced ifto tube' lythe various connections .Inade as showin the stopper 16 'turned tof open position andthe apparatus left to itself 'whereby the amount or heat' absorbed bythfe'tub'e 1 fro'fthe atmosphere will crc# ate 'a slow steady vflow'of'sulphur dioxide.

As soon as this initial passage o'frsulphur dioxide has been effected (one of its main Objects being to replace the air in the bulby 1 and i sausage affidi s a is din-0a @agente com letely with sulphur `dioxide which'` is nuc heavier) the stopper 16 is clo'sed, the connection 20 removed, the tube 1() replaced by the stopper 19 Vland the bulb weighed with thehighest possible accuracy.

In' order to'fconduct la'tes't afresh repre-V sentative sample of l1GO c.'V c. ofthe sulphur dioxide liquid is introduced intothe'clea-ii and dry tube 1, this tube being preferably at about room temperature. It ythen quickly closed by thev stopper 3 inorder toi minimizej the opportunity olii 'absorbing' moisture tronithe atmosphere) and" the ap'- p'aratus connected as shown iny the drawings' and the sulphur dioxide allowed to evapo-V rate' natufrally at room temperature until as ni'uchot the' saine has disappeared as Will pass oft under these conditions. This ordinarily requiresV several hours" although'it can be `accelerated by gentile heating. lfo'vvev'er,` itis" best to allow plenty ottime. The tube"1 is theniv `warmed to rooni temperature (the eva-porationof the' sulphur dioxide always c'o'ols itv much below thispoint) the' stopper 16 is turned olf, the conneetio'nZO' removed,l and ther tubel 10 iaga-in :replaed bythe stopper 19', and thebulb againwveighed. The' total aiic'lu'itVV o'f1V water" present is the sum df the ,wgllt'remidigin the tube 1 the Vincrease in weight ot tliefabsorption tube. W'

1. Iir cas: the arnori-ntf oil/liquid remaining iii the bottoni fthe tube issuicietto till the e Mpg-f ferres-geruis@ adresses. f ordinarily the rsiduesroaia ser isere than 11s-1r au ure si suer"- edge elegans reduced te percentage by applicaties de mestruale prv/1.49, herein Pzpercentage of Water by weight and 1.49 is the speciiic gravity of liquid sulphur dioxide. Thus in case the tube shows a residuo of .03 c. c. the percentage ot water corresponding thereto 1s .oanaezoao Part of the water content also distills away with the sulphur dioxide and is caught by the absorption tube. Assuming that the saine has increased in weight by an amount ot .275 g1ain,'tli`e saine rorniula is applied, namely P:.075/1.f19:.018%. Accordingly the total percentage of water present in the sanipl'e was :O20-{11018::0382

Itis also possible and iswithin my inven-v tion to calibrate thev prolonge of the tube 1 so asto exhibit directlythe percentage ot waterpreserit which requires merelypthat the value ,of the calibration be increased 19% over what it would be to readin cubic centi#v meters; and it islilew'ise possibleby making' up a special set `or weights with whichv to weigh the absorption tube, such wei'glitsbe# ing increased in mass 49% over Vstandard graniweights, t'oweigh the absorption tube directly in terms of water percentage.4 Y

In' many cases, however', -weighing of the absorption tubecan be dispensed with,` and even thev tube itsell omitted," although' some kind of a closure 3 and tube 1Ql slibuld still be employed to prei/'ent the cold sulphur dioxide from absorbing moisture from the atmosphere. E xperienceV shows thatl if the evaporation in tube 1 be conducted lalways under approximately the-same 'conditions as regards access of heat;`thc amount of water vaporwhiclrdistills over with the sulphur dioxideV always bears approximately the same ratio' to the amount left behind. Accordingly it is' entirely possible to calibrate the tube 1 with this in view,.the calibrations ot the prolongs not only being adjusted for the specific gravityofsulphur dioxide' but also for the amount of Water which passedaway als vapor. ThisV mode or procedure avoids allgwe'iglrin'g; allhan'dling of chemicals, and affords' a determination sufficient-ly exact tory most` purposes It is' important', however',4 in this'jc'as'e, to force the 'sulpliur dioxide to evaporate at a uniform rate, andy to compel this I prefer to enclose it in a suitable jacket' which shall both hold it'up'right cent offwate'r corresponding to* a volunie of sulphur dioxide indicated by' die mark 30;

' given specimen is or is not usable.

Needless to say this need not correspond to 100 c'. c. or any other established quantity. It is best designated Fill to here or equivalent expression.

The top of the tube l is preferably provided With a stopper 3 and dischargetube 10 as before to prevent deposition of dew from the atmosphere, and instead of a sulphuric acid seal I have shown the end of the tube 10 as drawn down to a line orifice 32 through which the sulphur dioxide vapor issues in the form of a fine jet which prevents the counteriiow of air. A. rubber tube 83 carries the vapor to any desired point of discharge.

The last described apparatus is not so accurate as that first described in the hands Vof* a skilled analyst but is more accurate in the hands of a careless Worker and is generally sufficiently accurate to determine Whether a In case the amount of Water remaining in the tube is more than suiiicient to lill the prolongs, it is ob-vious that no reading of its percentage is possible, but this has no practical disadvantage since such an amount of Water is sufficient to render the liquid valueless for the purpose in vievv. Ity will be obvious that many changes can be made Within the scope of my invention Wherefore I do not limit `myself in anyWise except as specifically recited in inv several claims which I'desire may be construed, each independently of limitations contained 1n other claims.

vapor by reference to the specific gravity of liquid sulphury dioxide. n

2. The method ofdetermining approximately the percentage of water in `liquid sulphurdioxide which contains the steps of evaporating a measured volume of such liquid at a yslovv rate in a conlined space Without access `of `air under substantially standard Vroom-temperature conditions until the readily vaporizable substances have substantially escaped, measuring the volume of liquid remaining at such temperature, adding an equal amount to represent the amount of moisture carried olf 'with the vapor, dividing that sum bythe specific gravity of liquid sulphur dioxide, and reducing the result to a percentage of the original sample by volume. p

In testimony whereof I hereunto aiiiX my signature;

WILLIAM C. BEVER. 

